Genuine versus non-genuine atomic multicast protocolsSchiper, NicolasFacoltà di scienze informatiche, Università della Svizzera italiana, SvizzeraSutra, PierreUniversité Paris VI and INRIA Rocquencourt, Paris, FrancePedone, FernandoFacoltà di scienze informatiche, Università della Svizzera italiana, SvizzeratextarticlePreprintdocumentUniversità della Svizzera italianaLuganoengapplication/pdf11 p.In this paper, we study atomic multicast, a fundamental abstraction for building fault-tolerant systems. We suppose a system composed of data centers, or groups, that host many processes connected through high-end local links; a few groups exist, interconnected through high-latency communication links. In this context, a recent paper has shown that no multicast protocol can deliver messages addressed to multiple groups in one inter-group delay and be genuine, i.e., to deliver a message m, only the addressees of m are involved in the protocol. We first survey and analytically compare existing multicast algorithms to identify latency-optimal multicast algorithms. We then propose a non-genuine multicast protocol that may deliver messages addressed to multiple groups in one inter-group delay. Experimental comparisons against a latency-optimal genuine protocol show that the non-genuine protocol offers better performance in all considered scenarios, except in large and highly loaded systems. To complete our study, we also evaluate a latency-optimal protocol that tolerates disasters, i.e., group crashes.004http://doc.rero.ch/record/22106/files/ITR0901.pdfhttp://doc.rero.ch/record/22106/files/ITR0901.pdfhttp://doc.rero.ch/record/2210620150420164016.022106